Gas and water distribution systems in cities and towns are laid out in a manner intended to serve a maximum number of users or customers with a minimum utilization of pipe. In such a system a single main may serve a very large number of customers.
Quite frequently such mains are ruptured, due either to natural or man-made occurrences. Whether conditions such as floods, earthquakes or extreme temperature changes can cause the pipe or conduit to be shifted in its position or stressed to the extent that is experiences fracture or separation. Construction of streets, sewage systems, installation of underground electrical distribution and other such operations involving excavation or trenching are common causes of broken or ruptured water and gas mains. Oxidation, galvanic action and other chemical reactions can also produce ruptures and leaks.
When such a rupture occurs it is important that repairs are made as quickly as possible to minimize safety hazards, as in the case of a broken gas main, and also to minimize the loss of the commodity being distributed.